Memory and the Brain

When older people can no longer remember names at a party, they tend to think that their brainpower is declining. But a growing number of studies suggest that this assumption is erroneous. Instead, the research finds, the aging brain is simply taking in more data and trying to sift through a clutter of information, often to its long-term benefit. (Source)

A study of the brains of people who stayed mentally sharp into their 80s and beyond challenges the notion that brain changes linked to mental decline and Alzheimer's disease are a normal, inevitable part of aging. In a presentation at the 239th National Meeting of the American Chemical Society (ACS 2010), Changiz Geula, Ph.D., described the first study of its kind involving elderly people with super-sharp memories. He said, “Environment, lifestyle, and genetics may be key factors. For example, some super-aged individuals might have a genetic predisposition to being super-aged, while others may help preserve high brain function by maintaining a healthy diet or staying physically active. Others may keep mental decline at bay by keeping the brain itself active: By reading books, playing crossword puzzles, or engaging in other mentally demanding activities.” (From the book Progress in Brain Research. Reported in New York Times, 2008.)

Improving your brain health can protect you from dementias, increase your memory, and sharpen concentration. Everything you do affects your brain and intellectual skills. Whenever you read a book or have a conversation, the experience causes physical changes in your brain,” says science writer George Johnson, author of In the Palaces of Memory. “It's a little frightening to think that every time you walk away from an encounter, your brain has been altered, sometimes permanently.” Pawlik-Kienlen outlines ten ways to increase your cognitive skills. (Pawlik-Kienlen, Laurie. 2008. How to Improve Your Brain Health: 10 Ways to Increase Memory, Concentration, and Cognitive Abilities. http://www.suite101.com/content/how-to-improve-your-brain-health-a53255#ixzz13QMzBaqZ)

There are several types of amnesia. “Dissociative fugue” (e.g., portrayed in the book/movie The Bourne Identity) is usually temporary and can be triggered by a very traumatic or stressful event. Rare, they affect less than 0.2% of people. (See multiple personality disorder. (On the Brain, newsletter. p 4. CA:2005.)

While amnesiacs have no conscious recollection of any new experience, they can learn many things nonconsciously (e.g., when given suggestions during surgery that they will recover quickly, they subsequently spend less time in the hospital than patients not given the suggestions, despite having no conscious memory of what was said while they were under anesthesia). (Wilson, Timothy D. Strangers to Ourselves. p 24-25. England: The Belknap Press of Harvard University Press, 2002.)

A form of amnesia that appears to be rooted in damage to the medial temporal lobes, especially the hippocampi. Person can recall information prior to an injury event but can no longer transfer information into long-term memory. (On the Brain, newsletter. CA:2005.)

Did you know that odors can trigger autobiographical memories very quickly? Researchers have used a variety of non-verbal cues in an attempt to trigger memories. Study results showed that odors are particular effective in triggering autobiographical memories, more so than other types of non-odor-related cues. Memories for specific events that were triggered by odors were more detailed and more emotionally loaded than memories triggers by verbal, visual, or non-odor-related cues. (Chu, S., & Downes, J. J. (2002). Proust nose best: Odors are better cues of autobiographical memory. Memory and Cognition, 30, 511-518.)

Autobiographical memory is a type of memory system that enables humans to recall events from his or her personal life. It is formed by a combination of personal experiences involving specific objects, people, and events that were experienced at a specific time and place (episodic memory) along with general facts and knowledge about the world (semantic memory). Most people have some autobiographical memory. A few individuals have been identified as having hyperthymesia or HSAM, Highly Superior Autobiographical Memory. (Williams, H. L., et al. 2008. Autobiographical memory. G. Cohen and M. A. Conway (Eds.), Memory in the Real World (3rd ed., pp. 21-90). Hove, UK: Psychology Press.)

In order to be yourself, you have to remember who you are. The specific memories, however, involve many brain systems and may not be available to you consciously. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 133. NY: Penguin Books, 2002.)

Dr. Lenore Terr, a child psychiatrist at the University of California Medical Center in San Francisco, studied children under the age of five who had experienced serious trauma from birth to 34 months. Results showed these children had retained behavior memories of their trauma which was reenacted in part or in entirety in their play. Traumatic events—especially those experienced early—may create “burned-in” images that last a lifetime. (Karr-Morse, Robin, and Meredith S. Wiley. Ghosts from the Nursery, Tracing the Roots of Violence. p 42. NY: The Atlantic Monthly Press, 1997.)

The memory of the sense of one’s body becomes so ingrained in the neural circuits governing self-experience that the brain has difficulty reorganizing itself after a crippling accident or stroke. A false belief can be constructed (e.g., man with phantom erections after penis removal; person ‘sees’ fat on their body where there is none in anorexia nervosa). fMRI scans showed that the sensory motor areas of the body do not distinguish between imaginary and actual images and activities. (Newberg, Andrew, MD and Mark Robert Waldman. Why We Believe What We Believe. P 61-62. NY: Free Press, 2006)

The memory of the sense of one’s body becomes so ingrained in the neural circuits governing self-experience that the brain has difficulty reorganizing itself after a crippling accident or stroke. If painful enough, the person may not be able to accept the truth. A false belief can be constructed, triggering an emotional memory that feels utterly present and real (e.g., man with phantom erections after penis removal; person "sees" fat on their body where there is none in anorexia nervosa). fMRI scans showed that the sensory motor areas of the body do not distinguish between imaginary and actual images and activities. (Newberg, Andrew, MD and Mark Robert Waldman. Why We Believe What We Believe. P 61-62. NY: Free Press, 2006)

Hebb has proposed that groups of neurons that fire together make up what he called a cell assembly. Neurons in the assembly can continue to fire after an event tht has triggered them and this persistence is a form of memroy. THinkinf is the sequential activation of assemblies. "Neurons that fire together, wire together. (Newberg, Andrew, MD. How God Changes Your Brain. p 13-14. NY: Ballantine Books, 2009)

Memories are made in individual cells. Regardless of type of memory, it is essentially the same process: an association forms between a group of neurons such that when one fires, they all fire, creating a specific pattern. Thoughts, sensory perceptions, ideas, hallucinations—any brain function (except random activity of a seizure) is made up of this same thing. (Carter, Rita, ed. Mapping the Mind. p 159. CA: University of California, 1998.)

Six cognitive functions (abstractive, quantitative, cause-and-effect, dualistic-oppositional, reductionist, holistic) work in conjunction with many other neural processes to create one’s belief systems. Some beliefs have strong emotional value and are deeply embedded in memory. Other beliefs elicit only mild responses and may never reach consciousness. (Newberg, Andrew, MD and Mark Robert Waldman. Why We Believe What We Believe. P 95-97. NY: Free Press, 2006)

We can have conscious access to the outcome of cognitive processes but are typically unaware of the processes that were involved in generating that content. Our perceptions, memories, and thoughts generally work in happy ignorance of the processes that make them possible. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 23. NY: Penguin Books, 2002.)

This term refers to one way in which the brain processes information. The person unknowingly does an action without the usual subjective feeling that accompanies willed action. There is a split between intention and conscious awareness, on the one hand, and the carrying out of a complex series of manoeuvres, on the other. Michael Faraday discovered this during investigations of table-turning session, Ouija boards, and automatic writing. (Restak, Richard, MD. The Naked Brain. p 26-27. NY: Three Rivers Press, 2006.)

Did you know that studies at UCLA have challenged theories of brain communication during sleep (e.g., the hippocampus talks to the neocortex). Studies showed there are three players: the neocortex, the hippocampus, and the entorhinal cortex or EC (which connects the neocortex and the hippocampus). And the neocortex is driving the entorhinal cortex, which in turn behaves as if it is remembering something, which then drives the hippocampus. According to Mehta, “This suggests that whatever is happening during sleep is not happening the way we thought it was. There are more players involved so the dialogue is far more complex, and the direction of the communication is the opposite of what was thought.” This process may occur during sleep as a way to unclutter memories and delete information that was processed during the day but is irrelevant, which results in important memories becoming more salient and readily accessible. Notably, Alzheimer’s disease starts in the entorhinal cortex and those individuals tend to have impaired sleep in addition to memory challenges. (Source)

Chronic stress can increase cortisol levels. The hippocapus is very rich in cortisol receptors so increased cortisol and disconnect existing neural networks, decrease capacity to learn, and contribute to memory loss. An exteme form of this type of memory loss can be seen in clinical conditions such as extreme depression and PTSD. (Goleman, Daniel Jay, PhD. The Brain and Emotional Intelligence: New Insights. p 46-50. MA: More Than Sound, 2011)

Short-term memory is best in the morning and lease effective in the afternoon; long-term memory is generally best in the afternoon. (Jensen, Eric. Brain-Based Learning (Revised). p 42. CA: The Brain Store, 2005.)

Declarative Memory or Explicit Memory refers to one of two types of long-term human memory. These labels refer to memories that you can consciously recall and tell (declare) to others should you choose to do so. Declarative/Explicit memory can be divided into two categories: Episodic memory that stores specific personal experiences (where you went on vacation last year); Semantic memory that stores factual information (your name and birthdate) and reflects the general knowledge you have gained about the world. For most people, these types of memory eventually tend to weaken with age.(Ullman, M. T. Contributions of memory circuits to language: the declarative/procedural model. Cognition 2004; 92: 231–270)

Declarative or Explicit Memory refers to the ability to consciously recall information, and to be able to state or declare it (e.g., name, phone number). Refer to Implicit Memory for additional information about another type of memory. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 97-98, 108-109, 192. NY: Penguin Books, 2002.)

Explicit episodic memories are about personal experiences and are characteristic of humans. The prefrontal cortex is activated during encoding and retrieval. Refer to Semantic Memory for additional Information. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 108-109, 192. NY: Penguin Books, 2002.)

Explicit semantic memories are about facts (and within the capacity of many animals). Refer to Explicit Memory for additional information. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 108-109, 192. NY:Penguin Books, 2002.)

Years later, a change can occur in a person’s life that allows recall of a traumatic event to come to conscious awareness. Degree of accuracy may be related to conditions of the recall. (Siegel, Daniel J. The Developing Mind. NY: The Guilford Press, 1999.)

Did you know that every time your brain remembers something it distorts it? Study findings at Northwestern University found that your memories are modified during recall. It’s a bit like the old “phone game” many played as children. By the time the message is transmitted around the circle, the content can be light years different from the message that was whispered into the ear of the first person. That’s because human memories human memories are always adapting. Donna Bridge, researcher and lead author of the paper on the study recently published in the Journal of Neuroscience put it this way, “If you remember something in the context of a new environment and time, or if you are even in a different mood, your memories might integrate the new information.” (Source)

In order for the brain to consolidate an experience as an “emotional memory,” the experience or event must be very arousing to the individual’s brain. The arousal can be positive or negative. A very positive or a very negative arousal can cause a memory to be strongly retained.(Cahill, L., and J. L. McGaugh. 1998. “Mechanisms of emotional arousal and lasting declarative memory.” Trends in Neurosciences, 21(7):294-299).

Powerful emotions create strong memories; and memories, when coupled with language, are the basis for forming conscious beliefs. This level of belief is what we often call "knowledge," but if it doesn’t have an emotional appeal, the belief will not register deeply in a person’s mind. (Westbury, C., and D. Dennett. “Mining the past to construct the future: Memory and belief as forms of knowledge.” Memory, Brain, and Belief. P 20. MA: Harvard University Press. 2000.

The hippocampus utilizes emotions to help establish long-term memory. Very emotional events tend to be written into memory more strongly than nonemotional events. (Newberg, Andrew, MD and Mark Robert Waldman. Why We Believe What We Believe. P 32-34. NY: Free Press, 2006)

Strong emotion fixes specific moments in the memory; you are more likely to recall those times of strong emotion. Emotions can also amplify an experience. (Ornstein, Robert. Multimind. p 106-109. NY: Doubledday, 1986.)

Emotional arousal makes any memory stronger. When the memory is of a traumatic experience, persistence can be debilitating. As long as the degree of emotional arousal is moderate during memory formation, memory is strengthened. But if the arousal is strong, especially if it is highly stressful, memory is often impaired. (LeDoux, Joseph.Synaptic Self. p 133-222. NY: Penguin Books, 2002.)

Intense emotional states are remembered more readily than mundane activities. (Giuffre, Kenneth, MD. The Care and Feeding of Your Brain. p 48. NJ: Career Press, 1999.)

Memories are encoded in individual cells. All types of memory consist of the same essential thing: an association between a group of neurons such that when one fires, they all fire, creating a specific pattern. This applies to thoughts, sensory perceptions, ideas, hallucinations—any brain function except the random activity of a seizure. (Carter, Rita. Mapping the Mind. P159. CA: University of California Press, 1998.)

A form of Explicit memory, semantic memories are about facts (and within the capacity of many animals). Refer to Explicit Memory for additional information. (LeDoux, Joseph.Synaptic Self, How Our Brains Become Who We Are. p 108-109, 192. NY: Penguin Books, 2002.)

Memory is fallible. The more time that elapses the worse it is. Keep records of important information and convesations immediately after they happen. Magicians capitalize on this. They count on the fact that your poor memory will not permit you to recall accurately what happened on stage after the program is over. (Macknik, Stephen L. PhD and Susana Martinez-Conde PhD. Sleights of Mind. p 116-120. NY: Henry Holt and Company, 2010.)

The frontal lobes in small children are insufficiently developed to allow them to track carefully where an idea originated (e.g., first-hand experience, heard from someone else). They’re not “lying” per se; source memory isn’t yet developed sufficiently. (Bragdon, Allen D., and David Gamon PhD. Brains that Work a Little Bit Differently. p 12-14. NY: Barnes and Noble, 2000.)

It is possible to feel non-experienced recollections as true memories. And actual events can be forgotten. (Siegel, Daniel J. The Developing Mind. p 55-65. NY: The Guilford Press, 1999.)

Have you ever wondered if it is possible to create false memories? Studies have shown that with repeated recollection, a person can come to believe that something specific really happened or that it happened in a specific way that may not be completely accurate. With repeated recollection and rehearsal, false memories may become more and more like true memories, with more information and greater levels of details. (Heaps, C. M., and M. Nash. "Comparing recollective experience in true and false autobiographical memories." Journal of Experimental Psychology: Learning, Memory, and Cognition, 27, 920–930)

False memories do have characteristics that differentiate them from actual true memories. False memories generally have more of an observer perspective (as compared to a field perspective), less emotional intensity, less visual imagery, fewer details about the original event, and less information about the consequences that followed the event. (Rubin, D. C., R. S. Schrauf, and D. L. Greenberg. "Belief and recollection of autobiographical memories." Memory and Cognition, 31, 887–901)

Recent studies at Uppsala University have shown that it is possible to erase a fear memory. When you experience a fearful event, a long-lasting memory is created by the process of consolidation (based on the formation of proteins). According to Thomas Ågren, a doctoral candidate at the Department of Psychology and co-author of the study, when participants had the reconsolidation process interrupted, the fearful memory was rendered neutral and no longer incited fear. Using a fMRI scanner, the researchers were able to show that the traces of that memory also disappeared from the amygdala, a part of the brain that normally stores fearful memories. (Source)

Many people have had the experience of entering a room and forgetting what they were going to get or do in that room. Professor Gabriel Radvansky, Psychology Professor at University of Notre Dame, reported new research on this problem. According to Radvansky, “Entering or exiting through a doorway serves as an ‘event boundary’ in the mind, which separates episodes of activity and files them away.” Using college students as subjects, three experiments in both real and virtual environments were conducted. Subjects performed memory tasks while crossing a room and while exiting a doorway. Results showed that subjects forgot more after walking through a doorway compared to moving the same distance across a room, suggesting that the doorway or “event boundary” impedes one’s ability to retrieve thoughts or decisions made in a different room. (Source)

Memories form when a pattern is repeated frequently, or in circumstances that encourage it to be encoded. This is because each time a group of neurons fires together the tendency to do so again is increased. (Carter, Rita. Mapping the Mind. p 159. CA: University of California Press, 1998.)

The function that keeps future goals in mind in the present to help you stay on track with accomplishment. (Restak, Richard, MD. Mozart’s Brain and the Fighter Pilot. p 47-50. NY: Harmony Books, 2001.)

Memory and understanding seem to be coded on both sides of the brain. When you lose one hemisphere you can still remember what you learned before and can understand things. Skills that reside primarily in one side (e.g., math and language) automatically shift to the other side. (Chang, Maria L. Life With Half a Brain. 1991.)

Previously known as hyperthymesia, HSAMers is the label for a very few unusual individuals, people who can recall vast amounts of detail related to personal experiences and events in their lives. You may have seen a TV interview with actress Merilu Henner, who has written a book about her unusual HSAMer ability. This type of memory appears not to focus on practiced mnemonic strategies or on calendrical calculations (used by some individuals with autism or savant syndrome). Rather, they rely on an automatic and often somewhat obsessive process linked to their own personal mental calendar. (Parker, E. S.; L. Cahill; J. L. McGaugh, 2006. Psychology Press. A Case of Unusual Autobiographical Remembering, 12, 35–49)

AJ (Jill Price) is reportedly the first documented case of hyperthymesia or HSAM. (Highly Superior Autobiographical Memory). She had an exceptional ability to recall autobiographical information along with events she had read about or personally seen on the news. Interestingly, she apparently was not very good at memorizing arbitrary information. Hyperthymestic individuals appear to have poorer than average memory for arbitrary information. (Berg, Tom. "Remembering every day of your life". The Orange County Register. April 25, 2008. Page 2. Jill Price.)

Did you know that only a handful of individuals have been identified as having extraordinary recall for personal life events? James McGaugh, a memory researcher at UC Irvine, reportedly invented the name hyperthymesia (from the Greek wordsthymesis meaning remembering and hyper meaning excessive). First described in a 2006 Neurocase article, people with hyperthymesia (typically not autistic) exhibit a couple of defining characteristics: they tend to spend a large amount of time thinking about their personal past coupled with an extraordinary capacity for recall. (Parker, E.S., L. Cahill, and J. L. McGaugh. A case of unusual autobiographical remembering.Neurocase 12 (1): 35–49, 2006)

The hippocampus acts as a clearing house. Sifts through incoming information from the cortex and decides what to store or discard. Its decision to store a memory hinges on whether the information has emotional significance, or whether it relates to something we already know. (Katz, Lawrence C., PhD and Manning Rubin. Keep Your Brain Alive. p.10. NY: Workman Publishing Company, Inc., 1999.)

The hippocampusIs believed to control memories after the age of three. (Pearce, Joseph Chilton. The Biology of Transcendence. p 36-40. VT: Park Street Press, 2002.)

Implicit or Nondeclarative Memory refers to memories that are reflected in the way we act more than in what we consciously know. They are formed by systems that engage in domain-specific learning. Refer to Explicit Memory for additional information. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 97-98. NY: Penguin Books, 2002.)

Implicit memory involves brain portions that do not require conscious processing either during encoding or retrieval. Somatosensory (bodily) memory is likely a form of implicit memory. (Siegel, Daniel J. The Developing Mind. p 28-38. NY: The Guilford Press, 1999.)

Implicit memory or knowledge (or tacit knowledge) is the type of knowledge wherein you can successfully ride a bicycle, for example, although you are unable to explain to someone else exactly how you are able to do so. (Restak, Richard, MD. The Naked Brain. p 23-24. NY: Three Rivers Press, 2006.)

Distortions in memory can extend beyond the intensity of the experience and impact the content of what is remembered. Memories of emotional experiences are often significantly different from what actually happened. Studies by Elizabeth Loftus: in many instances vivid memories of crime scenes turn out to be inaccurate, if unintentionally so. (LeDoux, Joseph. Synaptic Self. p 203. NY: Penguin Books, 2002.)

Intelligent or Creative Memory is being touted as the new model of the brain. It is one in which analysis and intuition work together in the mind in all modes of thought as it processes concepts and ideas. Reportedly, this type of memory can strengthen with age if a person decides to hone it. The Google story is but one of countless examples of this type of whole-brained thinking. Neuroscientist Barry Gordon , with coauthor Lisa Berger, provided an overview of this newer model of the brain in his book Intelligent Memory: Improve the Memory That Makes You Smarter. (Duggan, William. How Aha! Really Happens.Source)

For many people, intelligent memory is at the core of their success in life. It may be the most important factor that they can influence. (Gordon, Barry, MD, PhD, and Lisa Berger. Intelligent Memory. p xiv-xv. NY: Penguin Group, 2003.)

A study from the Montreal Neurological Institute and Hospital (The Neuro) of McGill University reveals that different patterns of training and learning lead to different types of memory formation. In every organism studied, results have shown that memory formation is highly sensitive not only to the total amount of training, but also to the pattern of trials used during training. In particular, trials distributed over time are superior at generating long-term memories than trials presented at very short intervals. (Source)

Long term memory is a more permanent type of memory that can last from days to years… Memory consolidation refers to the reinforcement that can result from the frequent retrieval of a piece of information. (Tortora, Gerard J., and Sandra R. Grabowski. Principles of Anatomy and Physiology, 10th Edition. p 520. NY: John Wiley & Sons, Inc., 2003.)

Nerve cells must do at least three things for long-term memory of behavioral processes to occur. These are to:

Some researchers believe that a permanent record of our past is hidden away in the brain, somewhere in the billions of neurons. This occurs regardless of whether or not we can recall those experiences. (Furlow, Bryant. You Must Remember This. New Scientist, 2001.)

When you see a person you care about, the stimulus goes from the visual system to the prefrontal cortex (putting an image of the loved one in working memory). The stimulus also reaches the explicit memory system of the temporal lobe and activates memories about that person. Working memory then retrieves relevant memories and integrates them with the image of the person. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 232-234. NY: Penguin Books, 2002.)

Were you under the impression that the human brain had already been mapped? Only partially. Recently, researchers in Germany (think of them as brain explorers) have found two new brain areas. They're at the front of the brain in a region known as the Frontal Pole, a portion already known to be associated with working memory and with social cognition and emotion processing. These two new brain areas have been named FP1 and FP2 (sounds a bit like Star Wars!). According to researcher Katrin Amunts, it took nearly three years to isolate and identify these two new areas. "Every time it's like a new continent, and it's surprising to find more and more areas," she said. Researchers estimate there may be 200 separate areas of the brain. Their goal is to have most of them identified on a brain map within five years. (Source)

As compared with natural memory, some individuals have learned to develop artificial memory through the process of learning and practicing memory techniques. Known as mnemonists, they use specific memory aids (such as mnemonic strategies) to help them recall long lists or groups of information. The mnemonic strategy can be a special phrase, acronym, short poem, or peg words/pictures. While the mind typically has difficulty recalling abstract concepts like numbers, it can often recall visual images quite easily. The mnemonic major system is a common technique for converting numbers into visual images that are then placed along points of an imaginary memory journey in the correct sequence. (Source)

Neurosychologist Alexander Luria reportedly diagnosed an especially strong form of synaesthesia (five-fold synaesthesia) in a Russian mnemonist named Solomon Veniaminovich Shereshevsky. Reportedly, the stimulation of one of his senses would result in a reaction in every other sense. For example, if Solomon heard a musical tone played he would immediately see a color, touch would trigger a taste sensation, and so on. (Luria, Aleksandr Romanovich. 1987. The mind of a mnemonist: a little book about a vast memory. Cambridge: Harvard University Press. pp. 31. ISBN0-674-57622-5)

Memory can be enhanced through music. It has mnemonic power (e.g., words of songs can be recalled more accurately than most prose). (Storr, Anthony. Music and the Mind. p 21-23. NY: Ballantine Books, 1992.)

Names are more difficult to learn and to recall than some other facts about individuals such as their occupation. (Source)

Elderly tend to believe they do worse than younger people at recalling names. (Source)

When older people can no longer remember names at a party, they tend to think that their brainpower is declining. But a growing number of studies suggest that this assumption is erroneous. Instead, the research finds, the aging brain is simply taking in more data and trying to sift through a clutter of information, often to its long-term benefit. (Source)

Negative remarks and memories are more strongly encoded in the brain, and they are the most difficult memories to eradicate. (Newberg, Andrew, MD, and Mark Robert Waldman. How God Changes Your Brain—Breakthrough Findings from a Leading Neuroscientist. p 140-141. NY: Ballantine Books, 2009.)

All memories involve interactions among a group of neurons. When one fires, they all fire and create a specific pattern. (Carter, Rita, ed. Mapping the Mind. p 159. CA: University of California, 1998.)

Non-declarative or procedural memory is one of two types of long-term human memory. It refers to unconscious memories such as skills (e.g. learning to ride a bicycle, knowing how to play a musical instrument). For most people, this type of memory tends to weaken with age. (Tulving, E. and W. Donaldson, eds. 1972. Episodic and semantic memory. In Organization of Memory, pp. 381–403. Source)

Implicit or Non-declarative Memory refers to memories that are reflected in the way you act more than in what you consciously know. They are formed by systems that engage in domain-specific learning. Refer to Declarative or Explicit Memory for additional information. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 97-98. NY: Penguin Books, 2002.)

Managing your weight is a vital part of protecting your health. Studies of 8,000 twins showed that being overweight doubled the risk of dementia, and being obese quadrupled that risk. In another study, obese people who lost weight following bariatric surgery had significantly improved memory and concentration after 12 weeks. (Small, Gary, MD. Author of The Memory Bible and The Alzheimer's Prevention Program. The Mind Health Report, Special Report, 1011-REV1111)

Study: The stronger the odor, the more likely it was to bring to mind a vivid memory. Just as women found all odors stronger, they also reported more memories than men for every odor but gas. (Gilbert, Avery N., and Charles J. Wysocki. “The Smell Survey, 1.5 Million Participants.” p 524. National Geographic Society, October 1987.)

Hippocampus: Personal memories are encoded in the hippocampus. It is also responsible for spatial memory (in the right hemisphere). (Carter, Rita, Ed. Exploring Consciousness. p 29, 115. CA: University of California Press, 1998.)

Photographic or eidetic memory refers to the ability of an individual to recall large amounts of detailed and vivid visual images, sounds, and/or objects. Studies have found that children with photographic memory, after being shown a picture and asked to study it for about thirty minutes, are able to recall and maintain the image in their memory as vividly as if it were still there after the image has been removed. (Source)

Preventing memory loss will always be easier than restoring it. Contains many tips for eating and other life-style factors that can help to preserve memory. (Small, Gary, MD. The Memory Bible. p 2. NY: Hyperion, 2002.)

The best protection is to exercise the brain’s memory mechanisms. Unfortunately, the failure to actively flex one’s memory “muscles” can result in atrophy. (Restak, Richard, MD. Mozart’s Brain and the Fighter Pilot. p 52-53. NY: Harmony Books, 2001.)

Reported in March 23, 2000 issues of “Science:” The strengthening of nerve cell connections in the brain, believed to occur during learning and memory consolidation, can be largely explained by the movement of proteins called AMPA receptors into synapses. (Cold Spring Harbor Laboratory. New Link Uncovered In Nerve Cell Mechanism Thought To Power Learning And Memory. Science Daily. March 28, 2000. )

There is now some direct biological evidence related to recall, much of which has heretofore been almost entirely theoretical. When a distant memory comes to mind, at least some of the neurons that fire are the same ones that fired back when the event actually happened. In some cases, researchers have been able to identify specific memories in the participants a second or two before the individuals themselves became aware of / reported having them. (NYT.)

Each time you recall a specific event you brain releases chemical similar to those released when you originally inputted your impressions of the event. If you want to feel positive, recall positive memories. (Amen, Daniel G., MD. Change Your Brain Change Your Life. p 76-78. NY:Times Books, 1998.)

Within one hour, 60% of all we learn is forgotten--80% within one month. (Stine, Jean Marie. Double Your brain Power. p 13. NY:Prentice Hall, Inc. 1997.)

Research at the Wellcome Trust Centre for Neuroimaging at London’s University College have discovered an interesting phenomenon. It appears that past events leave unique memory traces in the brain’s hippocampus. These memory traces can be distinguished from one another using fMRI brain imaging scans. Volunteers, while inside a fMRI scanner, were asked to recall each of three films they had just seen. A computerized algorithm was able to identify which of the three films each volunteer was recalling just by analyzing the pattern of the volunteer’s brain activity. (Source)

Memories are encoded in neuron groups that, when configured in a certain way, can cause a memory to be retrieved and replayed in one’s mind’s ear. The difficulty in terms of recall usually involves finding the right cue to access the memory and properly configure one’s neural circuitry. Theoretically, if a person had the right cues, he or she could access any past experience. For a huge percentage of the population, music provides one of life’s greatest and oldest delights. In all of its aspects (e.g., listening, performing, and composing), music involves a complex and subtle interplay between the outside world, one’s organs of perception, and multiple regions in the brain. (Sternberg, Barbara, PhD. Music & the Brain. p 18-19. CA: Institute for natural Resources, Home-Study #2320, 2009).

There is now some direct biological evidence related to recall, much of which has heretofore been almost entirely theoretical. When a distant memory comes to mind, at least some of the neurons that fire are the same ones that fired back when the event actually happened. In some cases, researchers have been able to identify specific memories in the participants a second or two before the individuals themselves became aware of / reported having them. (Carey, Benedict. For the Brain, Remembering is like Reliving. NYT, September 2008.)

Strong emotional stimuli release hormones and neurotransmitters that help to embed an emotional memory in your neural circuitry. You tend to remember things in relation to how important they are to you and are more likely to recall strong negative emotional states than positive ones. (Childre, Doc and Howard Martin. The HeartMath Solution. CA: Harper SF, 1999.)

Individual memories are burned onto hundreds of receptors that are constantly in motion around nerve synapses. Some escape. A specific set of molecules catch these elusive receptors and take them to a recycling plant where they are reprocessed and returned to the synapse intact. (Duke University Medical Center. 2007, September 24. New Understanding of Basic Units Of Memory.Science Daily.)

Studies of brain breaks, Stanford University School of Medicine: participants recalled 25% more information when taking a 3-hour memory training course when they relaxed every muscle in body prior to taking the exam (compared to those who did not perform the relaxation exercise). (Greenwood-Robinson, Maggie, PhD. 20/20 Thinking. p 126. NY: Avery, Putnam Special Markets, 2003.)

Memories form when a pattern is repeated frequently or under circumstances that encourage the pattern to be encoded. Each time a group of neurons fires together the tendency to do so again is increased. (Carter, Rita, ed. Mapping the Mind. p 159. CA: University of California, 1998.)

Savant syndrome involves some exceptional abilities in areas of memory and/or other specialized areas (e.g., specific type of information, specific hobby or event) even when not specifically trying to memorize autobiographical data. One of the best-known examples of savant memory is that of the man on which the movie Rain Man was based. Kim Peek reportedly had savant memory for most information, not just specialized pieces, and was able to memorize large pieces of information from the age of 16 months of age. (Treffert, D. A., and G. W. Wallace. 2003. "Islands of Genius" (pdf). Scientific American.)

Short-term memory is the temporary ability to recall a few pieces of information (e.g., 7-10 pieces as in a telephone number) for seconds to minutes. (Tortora, Gerard J., and Sandra R. Grabowski. Principles of Anatomy and Physiology, 10th Edition. p 519. NY: John Wiley & Sons, Inc., 2003.)

Short-term or working memory is involved in all aspects of thinking and problem solving (e.g., read a menu and keep options in mind while listening to the specials). It accommodates one task at a time (e.g., a new task bumps out content of the old task). The average number of things you can keep active in working memory simultaneously is about seven. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 175-176. NY: Penguin Books, 2002.)

Some researches believe that memory consolidation occurs during sleep, and specifically that it is during sleep that the slow interweaving of information into cortical networks takes place. Although it has not yet been demonstrated that the hippocampal playback during sleep is actually read and used by the cortex, the existing data are consistent with the possibility. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 105-108. NY: Penguin Books, 2002.)

There are direct connections from the olfactory bulbs to the cortex, amygdalae (emotional center) and the hippocampus (memory). This may account for the strong memories and emotions that can be evoked by smells. (Katz, Lawrence C., PhD and Manning Rubin. Keep Your Brain Alive. p 10. NY: Workman Publishing Company, Inc., 1999.)

Memories are not bottled up inside neurons. They are stored in the connections between neurons linked by synapses. With new experiences, new connections are made between neurons and others are lost. In a sense, memories are not stored inside matter but in the spaces between them. (Fields, R. Douglas, PhD. The Other Brain. p 22. NY: Simon & Schuster, 2009.)

Studies at the University of Alabama in Birmingham: long-term memories may be stored and preserved by the addition of chemical caps called methyl groups onto our DNA, a process called DNA methylation. The cellular memory is passed on even when the cells are replaced. It appears that short-term memories form in the hippocampus and slowly turn into long-term memories in the cortex. (Powell, Devin. Memories may be Stored on your DNA. New Scientist, 2008.)

Many researchers believe that explicit memories are stored in the cortical systems that were involved in the initial processing of the stimulus, and that the hippocampus is needed to direct the storage process. (LeDoux, Joseph. Synaptic Self, How Our Brains Become Who We Are. p 105-108. NY: Penguin Books, 2002.)

Memories are stored not only in the brain, but in a psychosomatic network extending into the body. Memory is encoded or stored at the receptor level, which means that memory processes are emotion-driving and unconscious (but, like other receptor-mediated processes, can sometimes be made conscious). There is a very close intertwining of emotions and memory. Most people’s earliest and oldest memory is extremely emotion-laden. (Pert, Candace. Molecules of Emotion. p 143-144. NY: Scribner, 1997.)

To understand memory you have to look at individual cells, because that is where memories are made. (Carter, Rita. Mapping the Mind. p 159. CA: University of California Press, 1998.)

PET studies: It appears there is a default network that becomes active whenever the brain is not specifically occupied and breaks off when the brain has other tasks to attend to. The default network utilizes large amounts of glucose (e.g., to create amino acids and neurotransmitters), and more oxygen gram for gram that a beating heart. With strong connections to the hippocampus, this default network appears to be involved in selectively storing and updating memories. (Fox, Douglas. The Secret Life of the Brain. New Scientist. 2008.)

Chronic stress can increase cortisol levels. The hippocapus is very rich in cortisol receptors so increased cortisol and disconnect existing neural networks, decrease capacity to learn, and contribute to memory loss. An exteme form of this type of memory loss can be seen in clinical conditions such as extreme depression and PTSD. (Goleman, Daniel Jay, PhD. The Brain and Emotional Intelligence: New Insights. p 46-50. MA: More Than Sound, 2011)

Psychologists at the University of Wisconsin-Madison have figured out how stress interferes with one’s ability to pay attention, focus, and create working memory. Working memory is both short-term (seconds) and flexible, allowing the brain to hold a large amount of information close at hand to perform complex tasks. Without it, you would have forgotten the first half of this sentence while reading the second half. They watched neurons functioning in the brain’s prefrontal cortex, part of the brain that is vital to working memory. The neurons communicated on a scale of every thousandth of a second. In addition, they knew what they did one second to one-and-a-half seconds ago. In the presence of a stressor, however, while the neurons became even more active, they were reacting to other things and failed to retain information about what they did a second or so ago. The conclusion was that stress-related impairment of this mechanism is believed to contribute to the cognition-impairing actions of stress. (Source)

Studies: stress in children. Long-term family conflict interferes with the development of the hippocampus. A shrunken hippocampus has been linked to memory loss and other cognitive impairments. (Greenwood-Robinson, Maggie, PhD. 20/20 Thinking. p 226. NY: Avery, Putnam Special Markets, 2003.)

David Devilbiss, a scientist and lead author on a study published in the journal PLOS Computational Biology, there are dangers of stress-related distraction.“The literature tells us that stress plays a role in more than half of all workplace accidents, and a lot of people have to work under what we would consider a great deal of stress,” Devilbiss said. “Air traffic controllers need to concentrate and focus with a lot riding on their actions. People in the military have to carry out these thought processes in conditions that would be very distracting, and now we know that this distraction is happening at the level of individual cells in the brain.” Recent studies have demonstrated that rather than suppressing activity, stress modifies the nature of neuron activity. “Treatments that keep neurons on their self-stimulating task while shutting out distractions may help protect working memory.” (Source)

For many people, intelligent memory is at the core of their success in life. It may be the most important factor that they can influence. (Gordon, Barry, MD, PhD, and Lisa Berger. Intelligent Memory. p xiv-xv. NY: Penguin Group, 2003.)

Studies: People who watch more than 4 hours of TV on a daily basis tend to be irritable, depressed, restless, and bored, They also have problems concentrating, remembering things, and sleeping. (O’Brien, Mary, MD. Successful Aging. p 81-82. CA: Biomed General. 2007.)

University of Sussex, 1988: the brain seems to favor literal memory in the morning; it is better at integrating new information with prior learning in the afternoon. (Jensen, Eric. Brain-Based Learning (Revised). p 45. CA: The Brain Store, 2005.)